Transcript L.14.7

SC.912.L.14.7
Relate the structure of each of the
major plant organs and tissues to
physiological processes
IDENTIFY THE PRINCIPAL ORGANS AND
TISSUES OF SEED PLANTS: LEAVES
Function of Leaves
 Make food through
photosynthesis
 Site of gas exchange
 Respiration
 Photosynthesis
 Store food
TISSUES OF THE LEAF: EPIDERMIS
Stomata
Openings in the epidermis mainly located
on the underside of leaves
Allow for exchange of gases (CO2, O2, H2O)
Guard Cells
Two cells located on each side of stomata
Opens and closes stomata
Cuticle
 Waxy substance that covers the leaves &
stems
 Waterproof layer that keeps water in
plants
 Transparent to allow light to enter for
photosynthesis
TISSUES OF THE LEAF: MESOPHYLL LAYER
Palisade mesophyll
 Primary site of
photosynthesis
Spongy mesophyll
 Contains air &
chloroplasts
 Site of photosynthesis
and gas exchange
TISSUES OF THE LEAF
Vascular Bundles
 Transport system
 Called veins
 Found in spongy mesophyll
 Two Forms
 Phloem moves food from leaf to
the rest of the plant
 Xylem moves water & minerals
up from the roots to the leaves
LEAF TISSUE ORGANIZATION
IDENTIFY THE PRINCIPAL ORGANS AND
TISSUES OF SEED PLANTS: STEMS
Function of Stems
 Movement of materials
 Water & minerals from
roots to leaves
 Manufactured food from
leaves to roots
 Support leaves &
reproductive structures
 Food storage
EXTERNAL STEM STRUCTURE
Terminal Bud
 Bud on the end of the
stem.
Axillary Lateral Bud
 Bud on the side of the
stem.
INTERNAL STEM STRUCTURE
Xylem
 The tissue that transports water &
nutrients up from roots to stems &
leaves.
Phloem
 Tissue that transports food down
from leaves to roots.
Cambium
 Thin, green, actively growing tissue
located between bark & wood and
produces all new stems cells.
INTERNAL STEM STRUCTURE
Bark
 Old, inactive phloem.
Heartwood
 Old, inactive xylem.
Sapwood
 New, active xylem.
SPECIALIZED TYPES OF STEMS
Corms
Tubers
 Underground stem
 Solid, fleshy, scale
covered
 Food Storage Area
 Short, thick underground
stem
Bulb
Rhizomes
 Layers of fleshy scales
that overlap each other
 Underground stem
 Underground stems that
produce roots on the
lower surface and extend
leaves and flower shoots
above ground
Stolens
 Stem that grows
horizontally above the soil
surface
Corms
Bulbs
Stolons
Tubers
Rhizomes
IDENTIFY THE PRINCIPAL ORGANS AND
TISSUES OF SEED PLANTS: ROOTS
Functions
 Anchors the plant
 Absorbs water & minerals
 Stores food
DIFFERENT TYPES OF ROOTS
Tap Roots
Fibrous Roots
 One main root, no nodes
 Ideal for anchorage
 Penetration is greater for
water and food storage
 Many finely branched
secondary roots
 Shallow roots cover a large
area
 More efficient absorption
of water & minerals
 Roots hold the soil to
prevent erosion
Aerial Roots
 Clinging air roots
 Short roots that grow
horizontally from the stems
and fasten plant to a
support
 Absorptive air roots
 Absorb moisture from the
air
Tap
Aerial
Adventitious Roots
 Develop in places other than
nodes
 Form on cuttings & rhizomes
Fibrous
Adventitious
PARTS OF ROOTS
Root Cap
 Indicates growth of new cells
Root Hairs
 Tiny one celled hair-like
extensions of the epidermal
cells located near the tips of
roots.
 Increase surface area.
 Absorb water & minerals.
Internal structure of Roots
Much Like Those Of Stems With
Phloem, Cambium And Xylem Layer s
Phloem
 The outer layer.
 Carries food down the
plant.
Xylem
 The inner layer.
 Carries water & minerals
up to the stem.
IDENTIFY THE PRINCIPAL ORGANS AND TISSUES
OF SEED PLANTS: FLOWERS
Functions
 Contain the sexual organs for
the plant.
 Produces fruit, which
protects, nourishes and
carries seeds.
 Attracts insects for
pollination.
PARTS OF THE FLOWER
Petals
 Brightly colored
 Protects stamen & pistils.
 Attracts pollinating insects.
 Collectively called the corolla.
Sepals
 Outer covering of the flower
bud.
 Protects the stamens and
pistils when flower is in bud
stage.
FLOWER REPRODUCTION
The STAMEN is the male
reproductive part. It is made
up of
 Anther
 Produces pollen which
fertilize the ovules
 Filament
 Supports the anther
The PISTIL is the female
reproductive part. It is made up
of
 Ovary
 Enlarged portion at base of
pistil
 Produces ovules which
develop into seeds
 Stigma
 Holds the pollen grains
during fertilization
 Style
pistil
 Connects the stigma with the
ovary
 Supports the stigma so that
it can be pollinated